diff --git a/src/_pytest/_argcomplete.py b/src/_pytest/_argcomplete.py
index 120f09ff6..6a8083770 100644
--- a/src/_pytest/_argcomplete.py
+++ b/src/_pytest/_argcomplete.py
@@ -78,15 +78,15 @@ class FastFilesCompleter:
 
     def __call__(self, prefix: str, **kwargs: Any) -> List[str]:
         # Only called on non option completions.
-        if os.path.sep in prefix[1:]:
-            prefix_dir = len(os.path.dirname(prefix) + os.path.sep)
+        if os.sep in prefix[1:]:
+            prefix_dir = len(os.path.dirname(prefix) + os.sep)
         else:
             prefix_dir = 0
         completion = []
         globbed = []
         if "*" not in prefix and "?" not in prefix:
             # We are on unix, otherwise no bash.
-            if not prefix or prefix[-1] == os.path.sep:
+            if not prefix or prefix[-1] == os.sep:
                 globbed.extend(glob(prefix + ".*"))
             prefix += "*"
         globbed.extend(glob(prefix))
diff --git a/src/_pytest/_py/path.py b/src/_pytest/_py/path.py
index c3905d0d3..fb64830f8 100644
--- a/src/_pytest/_py/path.py
+++ b/src/_pytest/_py/path.py
@@ -796,7 +796,7 @@ class LocalPath:
             kw = {"exists": 1}
         return Checkers(self)._evaluate(kw)
 
-    _patternchars = set("*?[" + os.path.sep)
+    _patternchars = set("*?[" + os.sep)
 
     def listdir(self, fil=None, sort=None):
         """List directory contents, possibly filter by the given fil func
@@ -1128,7 +1128,7 @@ class LocalPath:
                 modfile = modfile[:-1]
             elif modfile.endswith("$py.class"):
                 modfile = modfile[:-9] + ".py"
-            if modfile.endswith(os.path.sep + "__init__.py"):
+            if modfile.endswith(os.sep + "__init__.py"):
                 if self.basename != "__init__.py":
                     modfile = modfile[:-12]
             try:
diff --git a/src/_pytest/assertion/rewrite.py b/src/_pytest/assertion/rewrite.py
index cb64a33c0..e2648029c 100644
--- a/src/_pytest/assertion/rewrite.py
+++ b/src/_pytest/assertion/rewrite.py
@@ -180,7 +180,7 @@ class AssertionRewritingHook(importlib.abc.MetaPathFinder, importlib.abc.Loader)
             for initial_path in self.session._initialpaths:
                 # Make something as c:/projects/my_project/path.py ->
                 #     ['c:', 'projects', 'my_project', 'path.py']
-                parts = str(initial_path).split(os.path.sep)
+                parts = str(initial_path).split(os.sep)
                 # add 'path' to basenames to be checked.
                 self._basenames_to_check_rewrite.add(os.path.splitext(parts[-1])[0])
 
diff --git a/src/_pytest/pathlib.py b/src/_pytest/pathlib.py
index 533335c66..1fc16f5cd 100644
--- a/src/_pytest/pathlib.py
+++ b/src/_pytest/pathlib.py
@@ -557,8 +557,8 @@ def import_path(
 
         if module_file.endswith((".pyc", ".pyo")):
             module_file = module_file[:-1]
-        if module_file.endswith(os.path.sep + "__init__.py"):
-            module_file = module_file[: -(len(os.path.sep + "__init__.py"))]
+        if module_file.endswith(os.sep + "__init__.py"):
+            module_file = module_file[: -(len(os.sep + "__init__.py"))]
 
         try:
             is_same = _is_same(str(path), module_file)